The standard case construction comprises interconnecting two shell-like elements by means of hinges and to lock them by locking means provided on either side. In the case of the conventional case construction, there are extremely limited possibilities of adapting to different transportation requirements (volume change, function change), because the enclosed volume cannot be carried as a result of the fixed interconnection of the shells.
Presently available case constructions with a variable volume consist inter alia of:
(a) fabric cases, with the disadvantage of poor protection of the articles transported, due to the soft outer wall, PA1 (b) cases with bellows integrated into the shells, but which only permit a limited volume change; PA1 (c) the so-called twin case, which comprises a conventional case, with additional hooks and locking elements, in order to receive an additional lateral case shell, but here again there are only relatively limited variability possibilities. PA1 protection against slipping by a rubber layer carrying projections, PA1 connecting element between two basic elements, PA1 outer pocket, PA1 carrier wall for different accessories, PA1 bellows elements, PA1 roller shutter, PA1 clothing receptacle, PA1 photographic pocket, PA1 receptacle for electronic equipment (computer, dictating machine, radio, tv) PA1 file container, PA1 hanging or suspended filing system container, PA1 transition element between too large basic frame and too small additional element.
U.S. Pat. No. 1,950,118 (Lifton, 1931) describes a case formed from at least one central part and two lateral covering parts, in which the central part can be folded up and packed into the lateral parts. The central part of the case according to this U.S. Patent is not rigid and does not have a .hoarfrost.-shaped profile. In addition, the joints 43 and detachable hinges 49 constitute obstacles in the inner area.
French Pat. No. 2,157,245 (Kalamozoo, 1971) teaches and claims a case with a rigid central part and fixed, removable side walls. The central part has an inner, rigid partition 11 with two compartments 15, 18 and the side walls have studs for receiving perforated papers, probably computer outputs. Thus, the case according to this French Patent lacks the obstacle-free inner area in the central part, whose strength is achieved by destroying the inner free area by incorporating a partition, as well as the .hoarfrost.-shaped profile of the basic frame element. The locking elements 13 project and the carrying handle 12 cannot be lowered.
French Pat. No. 982,799 (ALFINA, 1949) relates to a case comprising a plurality of elements, between which the case can be opened, in order to everywhere have free access to the case content, even if the latter has a considerable depth (p.1, left-hand column, lines 1 to 4 of the description). However, the case has a complicated internal partitioning, cf FIGS. 3, 4 and 5. One embodiment of this invention only has a central part (FIG. 2). Furthermore, the case according to FIG. 2 of this French Patent does not show the internal, obstacle-free strength-imparting basic frame element with a .hoarfrost.-shaped profile.
DOS No. 2,213,267 (ROEHRICHT, 1972) claims a case whose strength results from a rigid partition 3 in the central area, in the same way as in French Pat. No. 2,157,245. In addition, parts of the case sides are not formed by the central parts, but by lateral parts 6. At these points, the central part is essentially only the rigid partition. The profile of the case according to FIGS. 4 to 6 of this DOS is not .hoarfrost.-shaped throughout, the inner area is not free from obstacles and is not possible to incorporate additional elements all round the profile.